Question

What might be a biological consequence of the fact that most enzymes operate only within very specific environmental conditions? How could this limit the activities of an organism?

Answer 1

Enzymes are biocatalysts that mediate many biological reactions. Each enzyme functions at a specific temperature and pH range. These conditions are known as optimal conditions. Most enzymes show maximum function at 37'C and neutral pH. Some enzymes function at acidic pH (Ex: Lysosomal enzymes). Some enzymes show optimal activity at a very high temperature (Ex: Taq polymerase shows optimal function at 72'C).

Beyond optimal conditions, enzymes show less function. At extreme conditions such as high/low pH or high/low temperature, enzymes become denatured.

The functional range of enzymes determines the ecological range of an organism.

For example, acidophilic bacteria contain many cellular enzymes which function at very low pH.

Thermophilic organisms contain cellular enzymes which function at high temperatures.